128 



PROCEEDINGS OF THE AMERICAN ACADEMY 



the boiling solution until a distinctly acid reaction is obtained, alcohol 

 in excess precipitates a white indistinctly crystalline salt. This dis- 

 solves ..very readily in water, but gives on evaporation a gummy mass, 

 and distinct crystals cannot be obtained. The solution of this salt 

 gives no precipitate at first with salts of potassium, but after a short 

 time beautiful colorless crystals are formed in abundance. The 

 salt dissolves in a rather large excess of water, leaving a small quan- 

 tity of a white insoluble compound. It crystallizes best from a solu- 

 tion which is not very concentrated, and which is allowed to evaporate 

 spontaneously in the air. The crystals obtained in this way are color- 

 less and well-defined prisms. On re-solution it almost always leaves 

 a small quantity of the slightly soluble salt; but when the whole is 

 dissolved together, the more soluble compound crystallizes without 

 perceptible admixture of the other. From very concentrated solu- 

 tions I obtained a white graiuilar salt, which, on re-solution in a 

 rather large quantity of water, gave the colorless crystals again. 

 Of the colorless transparent crystals, — 



1.1470 gr. gave 0.9372 gr. WO3 + P.O^ = 81.71% 



1.5149 gr. " 1.2:387 gr. " =81.77% 



1.3494 gr. lost 0.1089 gr. water r= 8.07% 



1.5806 gr. " 0.1277 gr. " = 8.08% 



1.1391 gr. gave 0.0498 gr. Mg^V^Oj = 2.80% Pp^ 

 1.1856 gr. « 0.0506 gr. " 

 1.5149 gr. « 0.4738 gr. AgCl 



These analyses correspond to the formula 



18 WO3 . P2O. . 6 K,0 + 23 aq. 



= 2.93% 



= 10.26% potassium. 



5298.4 100.00 

 Of the white granular hydrate, — 

 1.3868 gr. gave 1.0985 gr. WO3 -f P^O^ = 79.21% 



= 79.30% 

 = 2.57% PA 

 = 2.56% « 



0.9528 gr. " 0.7556 gr. " 



1.0396 gr. " 0.0409 gr. PgO^Mgg 



1.0614 gr. « 0.0425 gr. " 



1.0102 gr. lost on ignition 0.1009 gr. water 

 1.7974 gr. « « 0.1800 gr. " 



= 9.99% 

 = 10.01% 



